Unhealthy Rose

If roses are not fed properly signs of diseases and other problems will show up in the bush and flowers as the season progresses.
More than one thing wrong I think?
One is that it looks short of nutrients Because of the yellow leaves I would put Epsom salts around the bush and give an organic mulch.
In the spring use a slow release rose fertilizer. Apply at the start of the growing season when the higher Nitrogen ratio is good for new stem growth. The Potash and Phosphate ratios are enough to help the flowers and root system to develop growth later in the season.
It also needs spraying for diseases.
Just noticed is it under a fir tree? - think this might be the cause of the problems?

You would be able to move it to a better site over autumn/winter.

Are those two tree trunks I see, one directly behind the rose and one over to the right? If so, that's the problem - diffiicult for any plant to put down decent roots so close to trees, not to mention too much shade in the summer - roses prefer an open, sunny aspect, and do well in clay soil, though they will grow in other types as well.

That you all so much. I can see where I've gone wrong now. I set it to mask a conifer which I left in for privacy, I'll get it moved this autumn. It would be happier growing up an obelisk in an open sunny spot then. I've got some well rotted muck and I'll get some Epsom Salts and get it fed again in the Spring. Thanks again.

If it gets the sun, you can plant the rose further away from the conifer (so it has a freer root run) and train it to lean back towards the conifer by tying it to a tall garden cane

Hello Andrew - it does get the sun for half of the day, that's a good idea, thank you.